Approximately 10,000 years ago, the light produced by a massive star’s explosion in the constellation Vela reached Earth. As a result, the supernova formed a compact object known as a pulsar. However, It seems to illuminate periodically as it rotates, resembling a celestial lighthouse. The pulsar’s surface produces streams of particles that move near the speed of light. The particles generate an explosive mixture of charged particles and magnetic fields that collide with neighboring gas. Therefore, Astronomers refer to this event as a pulsar wind nebula.
Here is the question,
How does NASA’s IXPE Uncover Pulsar Wind Nebula Emissions?
IXPE is part of NASA’s Small Explorer mission lineup, launched aboard a Falcon 9 rocket from NASA’s Kennedy Space Center in Florida in December 2021. Currently, it orbits at an altitude of about 370 miles (595 kilometers) above Earth’s equator. The mission is a collaboration between NASA and the Italian Space Agency. Along with 13 countries contributing as partners and science collaborators. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations.
The recently captured picture shows a misty, light blue aura corresponding to Vela’s first-ever X-ray polarization data obtained from NASA’s Imaging X-ray Polarimetry Explorer (IXPE). A faint, indistinct blue line that extends towards the upper right-hand corner denotes a high-energy particle jet. As it emanates from the pulsar at roughly half the speed of light. Scientists believe that the pinkish X-ray “arcs” mark the borders of circular regions with a doughnut-like shape, where the pulsar wind produces shock waves and speeds up high-energy particles. One can identify the pulsar as the white circle at the image’s center.
Now, come to the point,
From where does IXPE gain Astrophysical Insights?
The NASA Chandra X-ray Observatory has observed Vela on multiple occasions, and the colors pink and purple represent its data. Meanwhile, the NASA Hubble Space Telescope captured the golden stars. By quantifying polarization, which pertains to the arrangement of electromagnetic waves, researchers can gain an unparalleled understanding.
Senior scientist at NASA’s Marshall Space Flight Center in Huntsville, Alabama, Phil Kaaret, says: “With IXPE, we are using extreme objects like Vela as a laboratory to investigate some of the most pressing questions in astrophysics. Such as how particles get catapulted to near the speed of light long after a star has exploded.”
Unprecedented Polarization in Vela Pulsar Wind Nebula X-rays:
The significant level of polarization took aback the scientists in the X-rays of the Vela pulsar wind nebula, as recent IXPE observations revealed. The astronomers reported findings in December in the journal Nature.
“This is the highest degree of polarization measured in a celestial X-ray source to date,” said professor Fei Xie of Guangxi University in Nanning, Guangxi, China, and a former postdoctoral researcher at Italy’s National Institute for Astrophysics/Institute of Space Astrophysics and Planetology (INAF/IAPS) in Rome, is the lead author of the Nature article.
When there is a lot of polarization, the electromagnetic fields are well-organized. They are all facing in the same direction, which depends on where they are in the nebula. Also, the X-rays that IXPE sees come from high-energy electrons spiraling in the magnetic fields of the pulsar wind nebula. This is called “synchrotron emission.” These magnetic fields must also be well organized when X-rays are highly polarized.
In contrast to supernova remnants that have a shell of material around them, the high polarization of the X-rays “suggests that the electrons were not sped up by the turbulent shocks that seem to be important in other X-ray sources,” said Roger W. Romani, a Stanford astrophysicist who helped analyze the IXPE data. Instead, there must be some other process, like magnetic reconnection, in which magnetic field lines are broken and put back together. That is one way that magnetic energy can be turned into particle energy.
So to get the point,
How IXPE Data Shows Vela Pulsar’s Magnetic Field Structure?
The analysis of IXPE data indicates that it has arranged the magnetic field surrounding the pulsar in a smooth, toroidal structure encircling its equator. It is consistent with what scientists anticipated.
Alessandro Di Marco is a researcher at Rome’s INAF/IAPS who helped analyze the data. He says: “This IXPE X-ray polarization measurement adds a missing piece of the Vela pulsar wind nebula puzzle.” Moreover, he says: “By mapping with unprecedented resolution, IXPE unveils the magnetic field in the central region, showing agreement with results obtained from radio images of the outer nebula.”
The Vela pulsar, situated approximately 1,000 light-years away from our planet, has a diameter of roughly 15 miles (25 kilometers) and completes 11 rotations every second, faster than a helicopter rotor’s speed.